<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
     <!-- 节点的优点 -->
     <div>我是div</div>
     <span>我是span</span>
     <ul>
         <li>我是li</li>
         <li>我是li</li>
         <li>我是li</li>
     </ul>
     <div class="demo">
     <div class="box">
         <span class="erweima">x</span>
     </div>
    </div>
     <script>
        //父节点 parentNode
        var erweima = document.querySelector('.erweima');
        // var box = document.querySelector('.box');
        //得到的是离元素最近的父级节点(亲爸爸) 如果找不到父节点就返回为null
        console.log(erweima.parentNode);

     </script>
</body>
</html>